WakeOnLan: Very very useful
When I was travelling over the holidays, I needed to get a file off my desktop, which was sitting back home in Cambridge in the same powered down state I left it in. Does this story sound familiar?
I have wakeonlan enabled so that I can power up the desktop from my laptop when I'm home, but I hadn't figured out how to do this remotely. I figured it was just a question of doing the right port forwarding, and that turns out to be the case.
DSLReports has a WOL tool that allows you to send the magic wake-up packet when you're out and about. Although there's some ambiguity in which packet to forward, UDP 9 to 192.168.1.255 worked for me.
Of course I figured this out *after* the holidays, but luckily I had enabled SneakerNet before leaving (i.e. the neighbor that fed the pets was able to turn it on the old fashioned way. Thanks Kristin)
Combine this with logmein.com, and you are your own thin-client ASP.